diff --git a/app/controllers/merge_requests_controller.rb b/app/controllers/merge_requests_controller.rb
index cb6a150fc..11241576f 100644
--- a/app/controllers/merge_requests_controller.rb
+++ b/app/controllers/merge_requests_controller.rb
@@ -1,14 +1,9 @@
 class MergeRequestsController < ApplicationController
   before_action :authenticate_user!
-  # before_action :authenticate_scope!
+  before_action :find_resource, only: %i[organisations update_organisations]
 
-  def create
-    @merge_request = MergeRequest.new
-  end  
-  
   def create
     @merge_request = MergeRequest.create!(merge_request_params)
-
     redirect_to merge_request_organisations_path(@merge_request)
   end
 
@@ -31,7 +26,28 @@ class MergeRequestsController < ApplicationController
     render "organisations"
   end
 
-  private
+  def update_organisations
+    if @merge_request.merging_organisation_ids
+      @merge_request.merging_organisation_ids << params[:merge_request][:merging_organisation].to_i
+      @merge_request.save!
+    else
+      @merge_request.update!(merging_organisation_ids: [params[:merge_request][:merging_organisation]])
+    end
+    @answer_options = organisations_answer_options
+    @merging_organisations_list = [@merge_request.requesting_organisation] + @merge_request.merging_organisations
+    render "organisations"
+  end
+
+private
+
+  def organisations_answer_options
+    answer_options = { "" => "Select an option" }
+
+    Organisation.all.pluck(:id, :name).each do |organisation|
+      answer_options[organisation[0]] = organisation[1]
+    end
+    answer_options
+  end
 
   def answer_options
     answer_options = { "" => "Select an option" }
@@ -43,10 +59,13 @@ class MergeRequestsController < ApplicationController
   end
   
   def merge_request_params
-    required_params = params.fetch(:merge_request, {}).permit(:requesting_organisation)
+    merge_params = params.fetch(:merge_request, {}).permit(:requesting_organisation)
 
-    required_params[:requesting_organisation] = current_user.organisation
-    required_params
+    merge_params[:requesting_organisation] = current_user.organisation
+    merge_params
   end
 
+  def find_resource
+    @merge_request = MergeRequest.find(params[:merge_request_id])
+  end
 end
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 009292c7f..1e0f888f6 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -1,5 +1,7 @@
 class MergeRequest < ApplicationRecord
   belongs_to :requesting_organisation, class_name: "Organisation"
+  # has_many :merging_organisations, class_name: "Organisation", primary_key: "merging_organisation_ids", foreign_key: "id"
+  # default_scope -> { select(column_names + ["merging_organisation_ids"]) }
 
   def merging_organisations
     Organisation.where(id: merging_organisation_ids)
diff --git a/app/views/merge_requests/organisations.html.erb b/app/views/merge_requests/organisations.html.erb
index a72b848c7..39144f7c1 100644
--- a/app/views/merge_requests/organisations.html.erb
+++ b/app/views/merge_requests/organisations.html.erb
@@ -1,7 +1,7 @@
 <% title = "Tell us if your organisation is merging" %>
 <% content_for :title, title %>
 <%# <%= govuk_back_link href: merge_request_organisation_path %>
-<h2 class="govuk-heading-l">Tell us if your organisation is merging</h2>
+<h2 class="govuk-heading-l">Which organisations are merging?</h2>
 
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds-from-desktop">
@@ -44,4 +44,4 @@
   <% end %>
 <% end %>
 <%= govuk_button_link_to "Continue", "#", button: true %>
-</div>
\ No newline at end of file
+</div>
diff --git a/config/routes.rb b/config/routes.rb
index c35509437..a3229068a 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -123,7 +123,7 @@ Rails.application.routes.draw do
     end
   end
 
-  resources :merge_requests, path: "/merge-request" do   
+  resources :merge_requests, path: "/merge-request" do
     post "merge-request", to: "merge_request#create_merge_request"
     get "organisations", to: "merge_requests#organisations"
     patch "organisations", to: "merge_requests#update_organisations"
diff --git a/spec/requests/merge_requests_controller_spec.rb b/spec/requests/merge_requests_controller_spec.rb
new file mode 100644
index 000000000..66a2cbb75
--- /dev/null
+++ b/spec/requests/merge_requests_controller_spec.rb
@@ -0,0 +1,47 @@
+require "rails_helper"
+
+RSpec.describe MergeRequestsController, type: :request do
+  let(:organisation) { user.organisation }
+  let!(:other_organisation) { FactoryBot.create(:organisation) }
+  let(:headers) { { "Accept" => "text/html" } }
+  let(:page) { Capybara::Node::Simple.new(response.body) }
+  let(:user) { FactoryBot.create(:user, :data_coordinator) }
+  let(:merge_request) { MergeRequest.create!(requesting_organisation: organisation) }
+
+  context "when user is signed in with a data coordinator user" do
+    before do
+      sign_in user
+    end
+
+    describe "#organisations" do
+      before do
+        organisation.update!(name: "Test Org")
+        post "/merge-request", headers:, params: {}
+      end
+
+      it "creates merge request with requesting organisation" do
+        follow_redirect!
+        expect(page).to have_content("Which organisations are merging?")
+        expect(page).to have_content("Test Org")
+        expect(page).not_to have_link("Remove")
+      end
+    end
+
+    describe "#update_organisations" do
+      let(:params) { { merge_request: { merging_organisation: other_organisation.id } } }
+
+      before do
+        other_organisation.update!(name: "Other Test Org")
+        patch "/merge-request/#{merge_request.id}/organisations", headers:, params:
+      end
+
+      it "updates the merge request" do
+        merge_request.reload
+        expect(merge_request.merging_organisations.count).to eq(1)
+        expect(page).to have_content("Test Org")
+        expect(page).to have_content("Other Test Org")
+        expect(page).to have_link("Remove")
+      end
+    end
+  end
+end
diff --git a/spec/requests/organisations_controller_spec.rb b/spec/requests/organisations_controller_spec.rb
index b16ee4750..d526f218f 100644
--- a/spec/requests/organisations_controller_spec.rb
+++ b/spec/requests/organisations_controller_spec.rb
@@ -441,7 +441,7 @@ RSpec.describe OrganisationsController, type: :request do
         end
       end
 
-      fdescribe "#merge" do
+      describe "#merge" do
         context "with an organisation that the user belongs to" do
           before do
             get "/organisations/#{organisation.id}/merge-request", headers:, params: {}
@@ -455,8 +455,8 @@ RSpec.describe OrganisationsController, type: :request do
             expect(page).to have_link("Back", href: "/organisations/#{organisation.id}")
           end
 
-          it "has a correct start no button" do
-            expect(page).to have_link("Start now", href: "/merge-request/new")
+          it "has a correct start now button" do
+            expect(page).to have_button("Start now")
           end
         end